This invention relates generally to stepping motors and more particularly to a compact, self-braking, high torque, precision magnetostrictive stepping motor particularly adapted for robotic applications.
Robot arms used in zero gravity environments, such as outer space, are typically powered by low torque, high speed electric motors which use transmissions as a means of torque multiplication and employ some type of braking system as a safety device when the power is shut off. Direct drive control is extremely desirable but heretofore included inherent limitations so as to be impractical and in some instances, unworkable. The addition of the transmission hardware and the associated braking apparatus renders the system bulky and extremely inefficient.
Stepping motors whose operation is based upon magnetostrictive principles are generally known and provide a means for alleviating the aforementioned problems and to exhibit enhanced precision in movement, safety and agility. Various types of magnetostrictive devices are generally known, including both linear and rotary motors. A rotary motor has a fundamental advantage over a linear motor in that a linear motor has a finite distance or stroke that it can travel. A rotary motor, on the other hand, makes multiple revolutions and thus it can move objects much farther than a linear motor. Also because a rotary motor can make many rotations, gearing techniques can be used to exchange this rotary motion for increases in torque, force, or speed depending on the particular application.
Accordingly, it is an object of the present invention to provide an improvement in electric motors.
It is another object of the invention to provide an improvement in stepping motors which provide a relatively high output torque.
It is still a further object of the invention to provide a magnetostrictive stepping motor which exhibits self-braking, precision rotational movement and direct drive to a load.
And it is still another object of the invention to provide a magnetostrictive drive motor which is particularly adapted for use with heavy duty applications including, but not necessarily limited to, zero gravity environments.